The present invention relates generally to a device for connecting a tube to a port in a housing. The present invention is particularly useful to connect a tube of an air conditioning circuit to a port associated with a component, such as an expansion device or compressor of the type generally used in automotive vehicle air-conditioning systems.
Many different types of tube mounting devices are known for attaching a tube to a component of an air conditioning system. A flexible refrigerant hose in an air conditioning system is typically provided with a rigid tube end fitting. The tube end fitting is then inserted into the port in the appropriate air conditioning component and attached to the air conditioning component using the mounting device. Many of such mounting devices include a connecting block with one (or more) openings extending through the block for receipt of one (or more) tubes. The tube(s) are received in the openings in the block and retained therein using different techniques, depending for the most part on the manufacturer. A bore extending through the block allows the connecting block to be easily fastened to an outer surface of the component with a fastener (e.g., a bolt), such that the tube is sealingly connected to the component. The connecting block facilitates the attachment of the tube(s) to the component in a simple and cost-effective manner, and is widely used in the industry.
U.S. Pat. No. 5,860,681 for example, shows a connecting block with a U-shaped recess interconnecting opposite end surfaces of the block along an axis, and opening outwardly from the side of the block, where a tube is inserted into the recess from the side of the block such that the longitudinal axis of the tube is located along the axis of the connecting block. An insert (clip) is then inserted into the recess to capture the tube by axially sliding the insert from one end surface of the block. The insert includes winged tabs extending axially along opposite sides of the insert which are received with a press-fit within corresponding axial slots in the recess, and a concave surface which corresponds to and is located against the diameter of the tube. While such a mounting device might be appropriate for particular applications, it is believed the insert can be difficult to slide into the recess from one end surface of the block. The insert also must typically pass over an annular bead or flange on the end of the tube as it is being pushed into the slot, which can make it difficult to push the insert fully into place and lock the tube in the block. It can also sometimes be difficult to access the end surface of the block to push the insert into the block.
Other techniques, for example as shown in U.S. Pat. No. 5,405,175, have clips with a complicated geometry which can be difficult and costly to manufacture. The clip shown in the ""175 reference includes a base, a fork projecting outwardly from the base, a pair of outwardly-opening channels on each side of the fork, and a catch located in each channel to grab notches formed in the enlarged receiving end of a tube.
Other techniques, such as shown in U.S. Pat. Nos. 4,635,974, 5,040,831 and 5,593,187, require the clip to have a spring function to hold the tube in the block. Should the clip lose its spring characteristic, the clip can fall out of the block and allow unintentional release of the tube from the block and/or components.
It is believed other techniques rely on system pressure to ensure rigid attachment of the clip to the connecting block. This can also be an unreliable technique for attaching the tube to the component in the event of fluctuations in system pressure.
Still other techniques do not allow selective control of the amount of rotation of the tube in the block during attachment. Such control can be useful or even necessary in some attachment applications.
As such, it is believed there is a demand for an improved mounting device for a tube, which allows selective control of the rotation of the tube captured in the block; is simple in construction and assembly, and relatively inexpensive to manufacture; and does not rely on a spring function or system pressure to maintain the attachment of the tube.
According to the present invention, the mounting device includes a connecting block and a clip, where the clip is inserted into a U-shaped recess in the block essentially perpendicular to the axis of the connecting block. The connecting block includes an elongated body having first and second parallel end surfaces extending perpendicular to the axis of the body, a circular opening axially interconnecting the surfaces toward one side of the body for receipt of a first tube; a circular opening axially interconnecting the surfaces in the central portion of the body for receipt of an attachment device (such as a threaded bolt); and a U-shaped recess axially interconnecting the surfaces toward another side of the body for receipt of a second of the tubes. The U-shaped recess opens outwardly from the side of the body and includes a U-shaped channel formed in the recess perpendicular to the axis and facing outwardly from the recess.
The clip has a U-shaped body, and a pair of resilient tabs extend outwardly from the body in parallel relation to one another. The tabs are closely received, preferably with a slip-fit, in opposite sides of the U-shaped channel. The tabs have a length such that when the clip is inserted into the U-shaped channel, the tabs are bent inwardly toward one another by the curved inner end of the channel to facilitate retaining the clip within the channel. The body also includes a flat, outwardly-projecting flange perpendicular to the tabs and facing the U-shaped channel. The flange is received within a notch or groove in the tube to rotationally orient the tube properly within the connecting block. The outer ends of the channel are then coined to retain the tabs, and hence the clip, within the body.
The clip further includes an extension projecting axially from the body of the clip. The extension includes a concave curved portion facing the U-shaped channel when the clip is inserted in the channel. The distal edge of the extension is located against a bead on the tube when the clip is inserted into the channel to axially fix the tube with respect to the connecting block. The sides of the extension fit tightly within the open mouth of the recess to retain the clip within the connecting block before the channels are coined.
It is a further aspect of the present invention that the connecting block could have two (or more) U-shaped recesses for retaining multiple tubes. In this case, the recesses could each have the same structure as described above, and an appropriate number of clips could be provided to retain the tubes within the respective recesses during assembly of the block with the air conditioning system component.
Further features and advantages of the present invention will become apparent from reviewing the following description and accompanying drawings.